Electromagnetic sewing machine



Nov. 26, V1940. F. oli-:HL ETAL 2,223,315

ELECTROMAGNET I C SEWING MACHINE Filed June2'7, 19259 3 Shests-SheerI 1 f77 @m I www,

Nav. 26, 1940. F. DIEHL E-rAL ELEGTROMAGNETIG vSEWING MACHINE Filed June 27, 1959 3 Sheets-Sheet 2 Syvum Nav. ze, 1940. F, DEH; ETAL 2,223,315

ELECTROMAGNET I C SEWING MACHINE Frederze Diehl 'md James M /Vu/Z Patented Nov. 26, 1940 UNITED STATES PATENT CFFICE Frederick Diehl, Elizabeth, and James M. Naul,

Fanwood, N. J., assignors to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application June 27, 1939, Serial No. 281,348

12 Claims.

`This invention relates to sewingmachines oi the type in which one or more of the component mechanisms of the machine is operated by electromagnetic means of the vibratory or oscillatory type as distinguished from the conventional electric motor which drives by a continuous rotary motion. x

The invention has for an object to provide a sewing machine with improved and simplied oscillatory electromagnetic means for actuating one of its component mechanisms. A further object of the invention is to provide a shuttle type machine with electrical means to time the oscillatory motion of the shuttle with reciprocatory motion of the needle. Still further, the invention has for an object to provide a sewing machine with independent, electrically interconnected devices for driving the needle and complemental loop-taker, so that there is n0 mechanicalV connection between the two component upper and lower elements of the stitchforming mechanism.

With the above and other objectsA in view, as

will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodi- .ment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those'skilled in the art.

Electric sewing machines as heretofore constructed with non-rotary electromagnetic driving devices, have commonly made use of pairs of solenoids, or one solenoid with a recovery spring, to move the actuated part alternately in opposite directions. When a recovery spring is used,

the` solenoid must be of double strength and never idle forv an appreciable time.

In the accompanying drawings Fig. 1 is a vertical longitudinal section of a sewing machine ,embodying the invention. Fig. 2 is a bottom 3-3, Fig. 1. Fig. 4 is a section on the line 4-4, Fig. 1. Fig. 5 is a section on the line 5 5, Fig. l. Fig. 6 is a disassembled perspective view of the intermediate and one end element of the universal joint driving connection between the lower oscillatory motor and the shuttle driving rocker. Fig. 7 is an electrical diagram of the lower oscillatory motor and the timer and Fig. 8 is a development of the rotary element of the timer.

- 'I'he machine has the conventional frame including the bed I, and hollow bracket-arm 2 terminating in the head 3 in which the usual reciprocatory needle-bar 4 and presser-bar 5 are mounted. The needle-bar carries the needle 6 and the presser-bar carries the presser-foot l.

'I'he needle-bar has the conventional link 8 and crank 9 connection with the `top-shaft I0 which is journaled in the bracket-arm 2 and carries the balance Wheel and belt-pulley II connected by the belt I2 to any suitable source of power, such as the conventional rotary sewing machine motor I3 mounted at the rear of the bracket-arm standard I4. The electric motor I3 is not, however, an essential part of the present sewing machine.

The take-up I5 is conventional and is actuated by the usual barrel-type cam I6, the take-up actuating groove I1 of which has been modified to cause the take-up I5 to give up thread rapidly before the shuttle is passed through the threadloop taken from the needle, so that there will be enough slack in the needle-thread for the rapidly advancing shuttle of the present machine. The present take-up has a fast down-motion as well asa fast up-motion.

Cooperating with the needle 6 to form stitches is the conventional oscillatory shuttle I8 which is journaled in the conventional shuttle-raceway I9 and driven by the conventional shuttle-driver 20 on the oscillatory shuttle-driving shaft 2| journaled in the bearing lugs 22 below the bed I. Fixed tothe rearward end of the shaft 2| is the usual crank-arm 23 carrying the pivoted bearing-block 24 which works in a forked arm 25 on the rock-shaft 26 journaledrin the bearing lug 21 and steadied by the pintle 28. The axis of the shafts 2| and 26 are oiiset, as shown in Fig. 3, so that a motion of the shaft 26 produces over oi motion of the shuttle-driving shaft 2|. which is enough to drive theshuttle completely through the thread-loop taken from the needle.

In the present machine, the shaft 26 oi the forked shuttle-driving rocker is connected through the conventional universal coupling 29 Ato the shaft 30 of the special oscillatory motor 3| which ismounted on the bracket 32 secured to the arm-standard I4. The universal coupling 29 comprises two opposed disks 33 each having diametrically opposed pins 34 entering holes 35 in the intermediate disk 36, of rubber, fiber, or the like.

The motor 3| has the usual eld-frame 31 and field-coil 38 of a conventional direct-current motor. The armature 39, however, has no commutator but has an armature Winding -40 arranged to polarize the armature; the terminals 40' of the Winding 40 extending through a hollow portion of the armature shaft 30, Figl 1, to the slip-rings 42 mounted on'the shaft 30. The slip-rings 42 are engaged by spring-pressed brushes 43. The field-coilsv have terminal connection wires 44. The polarity of the armature 39 may be reversed by reversing the current through the armature winding 40. .The oscillatory movements of the armature 39 are limited to approximately 100 by the rubber covered stop-pin 45, Fig. 5, 'mounted on the frame of the motor 3| and engaged -by the heads of the adjustable screws 4B on the arms 4'l'of the stopcollar 48 pinned to the armature shaft 38.

To control and time the shuttle-driving oscillations of the motor-shaft 30, there is mounted on the top-shaft l0, a conventional rotaryfeversing switch-cylinder 49, Fig. 1, carrying the cylindrical plates 50, 50 with stepped edges, as shown in Fig. 8. This contact cylinder is engaged by three brushes 5|, 52, 53, of which the brushes 5| and 53 bear continuously upon the respective cylinders 50, 50. The intermediate brush 52 bears alternately on the cylinders 50, 50'. Diametrically opposed to the brush 52 is the current lead-in brush 54, Fig. '7, connected to the line L or current supply. The timer or switch 49 has the effect, as the shaft IU rotates, of connecting the line L alternately to the brushes 5|, 53, the brush to which the line is not connected, being connected to the middle brush 52 which runs to the motor field and the other side of the line. The result is that the polarity of the armature is reversed relative to the polarity of the field and the timing of the reversals is controlled by the top-shaft |0. The timer 49 is positioned on the shaft lll so that when the needle 8 has risen slightly from the lower end of its stroke and has thrown out a loop of needle-thread, the polarity of the armature 39 is reversed and the latter is caused to move quickly in a direction to drive the shuttle through the needle-loop. When the needle reaches` the upper end of its stroke, the armature 39 executes a reverse motion and causes the shuttle to quickly recover its initial position ready to take the next needle-loop.

Either alternating or direct current may be used to energize the motor 3|. If direct current is used, a permanent magnetic field-frame may, of course,l be substituted for the electromagnetic field-frame, as the polarity of the field-poles is not reversed.

The oscillatory motor 49 executes an are of motion of only about 100 but, because of the intermediate fork 25 and crank 23, this motion is increased to about v195" of motion of the shuttledriving shaft 2|, necessary to drive the shuttle I8.

The feed-motion comprises the usual feed-bar 55, Fig. 2, pivoted at vlilith the upstanding arms 51 of the usual feed-rocker 58 which is actuated by the usual feed-pitman connection 59 having a forked upper end embracing the feed-cam 50 on the top-shaft I0. The feed-lift is obtained as usual from the cam 8| on the rocker 26. The cam 6| is embraced by the forked arm 62 of the feed-lift rock-shaft 53 having an arm 64, Fig. 2, which engages the front end of the feed-bar 55; all of the feed connections being conventional.

' The quick motion of the rocker 28 caused by the rapidly executed oscillations of the motor 3| effect a rapid lift of the feed-bar 55 at the beginning of the feed-stroke and a quick drop of the feed-bar at the end of the feed-stroke. Thus a substantially rectangular feed-path is traversed by the feed-dog 65 instead of the usual elliptical feed-path. A rectangular feed-path is perfectly nat-topped from beginning to end and is very desirable of accomplishment as is well known by those skilled in the sewing machine art.

The field iron of the motor is polarized by the field winding 38, and the armature iron is polarized by the armature winding 40. By `e versing the current in one of said windings relative to the other winding the armature is caused to quickly turn from one extreme position to its other extreme position. The polarizing winding 40 for the movable motor-element is in use for both directions of movement of said element and the need for two alternately excited coils, such as used in machines of the prior art, is thus eliminated and a more powerful motor for the weight of materials used is produced.

Having thus set forth the nature of the invention what We claim herein is:

1. A sewing machine having a reciprocatory needle, a top-shaft connected to drive said needle, a loop-taker complemental to said needle, an oscillatory loop-taker-driving shaft, an oscillatory electromagnetic motor connected to oscillate said loop-taker-driving shaft, and electrical switching means on said top-shaft, to time the oscillatory movements of said motor.

2. A sewing machine having a reciprocatory needle, a top needle-driving shaft, an oscillatory shuttle, an oscillatory shuttle-driving shaft, a rocker for driving said shuttle-driving shaft, a

motion amplifying connection between said rocker and shaft, and an oscillatory electromagnetic motor connected to oscillate said rocker.

3. A sewing machine having stitch-forming mechanism including an oscillatory stitch-forming element, a rotary,1 shaft, an oscillatory motor for driving said oscillatory element, said motor including field and armature windings, and means governed by the rotation of' said rotary shaft for reversing the current in one of said windings.

4. In a sewing machine, an oscillatory motor having a field magnet, an armature, an armature shaft whereby said armature is supported for oscillation in the field of said field magnet, an armature polarizing winding, a. rotary shaft, a current-reversing switch actuated by said shaft and connected to reverse the current in said armature winding, whereby the motor shaft is caused to oscillate in time with the rotation of said rotary shaft, and coacting stitch-forming devices actuated, respectively, by said oscillatory motor and said rotary shaft.

5. A sewing machine having a reciprocatory needle, a needle-driving shaft, an oscillatory shuttle, an oscillatory shuttle driving rocker, an oscillatory electromagnetic motor having a fieldframe and an oscillatoryv shaft and armature journaled in said field-frame, said oscillatory motor-shaft being directly connected to said rocker.

6. A sewing machine having a reciprocatory needle, a needle-driving shaft, an oscillatory shuttle4 driving rocker, an oscillatory electromagnetic motor having a field frame and an oscillatory shaft and amature journaled in said field-frame, said oscillatory motor-shaft being directly connected to said rocker, and adjustable stops on said oscillatory motor-shaft to limit the movements thereof in opposite directions.

7. In a sewing machine, an oscillatory motor comprising a field-frame, an armature, a shaft whereby said armature is rotatably supported in said field-frame, a field winding, a polarizing armature winding, a pair of slip-rings on said shaft connected to the terminals of said winding. stop means to limit oscillatory motion of said shaft in opposite directions, current reversing means connected to said armature winding, a rotary shaft for controlling and timing the operation of said current reversing means, and coacting stitch-forming devices actuated, respectively, by said oscillatory motor and said rotary shaft.

8.*A sewing machine having a reciprocatory needle, an oscillatory shuttle, an oscillatory electromagnetic motor connected to oscillate said shuttle, a rotary needle-driving shaft, and electric switch means controlled by said shaft to time the oscillations of said electromagnetic motor.

9. A sewing machine having a reciprocatory needle, an oscillatory shuttle, an oscillatory electromagnetic motor connected to oscillate said shuttle, a rotary needle-driving shaft, and electric switch means controlled by said shaft to time the oscillations of said electromagnetic motor, and a needle-thread take-up actuated by said rotary shaft and timed to complete its thread-giving stroke before the shuttle is actuated to take the needle-loop.

10. In a sewing machine, a reciprocatory needle, a loop-taker, a feed-bar, a feed-dog carried thereby, a rotary shaft and connections for reciprocating said needle and for imparting feedand-return movements to said feed-bar, oscillatory electromagnetic means to actuate said loop-taker and to impart rising and falling movements to said feed-bar, and means controlled by said rotary shaft to time said oscillatory electromagnetic means.

11. A sewing machine having stitch-forming mechanism including a reciprocatory needle-element, a complemental yloop-taker element, means to actuate one of said stitch-forming elements, an oscillatory electromagnetic motor connected to operate the other of said stitch-forming elements, said motor including relatively movable polarized field and amature elements and a polarizing winding for one of said motor elements, and current-reversing means for said polarizing winding -connected to be operated and timed by the means 'which actuates said one of said stitchforming elements.

12. In a s'ewing machine, the combination with two movable stitch-forming elements, of oscillatory electromagnetic means including a polarizing winding to operate one of said elements, and a current-reversing switch for said winding having a timing connection with the other of said elements.

FREDERICK DIEHL. JAMES M. NAUL.

Y CERTIFICATE CE CORRECTION. u Pam No. 2,225,515. November 26, 19m.

FREDERICK DIEHL, ET AL.

It is hereby -certfed that error appears in the printed specification of the above numbered patent requiring; corregton as follows: Page 2, first column, line l0; for v"field-coil 58 read --field-coils 58; page 5, first column, line 2, Claim 6, before "an" nsertthe wordsl and Comma --an oscillatory. shuttle,; and that the said vLetters Patent. should be read with this correction therein that the same may conform to the reCord of the Case in the Patent Office.

signed and saled this 51st day of December, A. D. IQLLO.

` Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

